KR100371256B1 - Preparation of magnetic head - Google Patents

Abstract

According to the present invention, a plurality of magnetic core semi-blocks are formed on one main surface by forming a plurality of track width restricting grooves on one main surface and forming a metal magnetic film made of a soft magnetic metal material on one main surface. To form a magnetic head block through a gap material, and when cutting the magnetic head block to form the head chip of the magnetic head, the track width restricting groove is made into a polygonal cross section and at least two curved portions are formed. By making it shape, it becomes possible to suppress the cracks which are easy to generate | occur | produce in a magnetic core at the time of manufacture, peeling of a magnetic metal film, etc., and to aim at the improvement of the yield and reliability of a product significantly.

Description

Preparation of the magnetic head

According to the present invention, a metal magnetic film made of a soft magnetic metal material is formed on one main surface, and a magnetic core half body is joined to each other at a magnetic gap surface. It relates to the manufacturing method of magnetic head of type).

In recent years, in magnetic recording and reproducing apparatuses such as video tape recorders and digital audio tape recorders, short wavelength recording of information signals has been carried out for the purpose of improving the image quality, and correspondingly, ferromagnetic metal powders have been applied to magnetic components. High antimagnetic magnetic recording media such as so-called metal tapes used and deposition tapes in which ferromagnetic metal materials are directly deposited on a base film are used.

In the field of magnetic heads, on the other hand, studies to cope with this are being conducted. So-called metal-in-gap magnetic heads (hereinafter, simply MIG) using a soft magnetic metal magnetic material as a core material as a magnetic head suitable for a high-constant magnetic recording medium are described below. Heads) have been developed.

In the manufacturing step, the MIG head is formed with a plurality of band-shaped track width regulating grooves 101 leaving a gap width interval on one main surface, as shown in FIG. A metal magnetic film 102 made of a soft magnetic metal material is formed on the gap surface M of the magnetic core half block 103.

Two magnetic core half blocks 103 produced in this way are prepared, and as shown in FIG. 2, the gap faces M of a pair of magnetic core half blocks 103 face each other. The openings 104 formed by the track width restricting grooves 101 formed in the pair of magnetic core half blocks 103 face each other to become track width restricting grooves. A glass material 105 for fusion is introduced into the opening 104 and joined to form a plurality of magnetic gaps g to form the magnetic head block 106.

From the magnetic head block 106, for example, each head chip is cut out to the required chip width along the broken line in FIG. 2, and the join width processing, winding, and the like are performed to form the MIG head.

The shape in the cross section orthogonal to the longitudinal direction of each track width regulation groove 101 formed in the magnetic core half block 103 is shown in FIG. 3 (each track width regulation groove 101 shown in FIGS. 1 and 2). As shown in FIG. 4 or FIG. 4, the magnetic head block 106 is formed in a substantially semicircular shape or one having a bent portion 111, and the magnetic core half blocks 103 are joined to each other at the gap surface M. As shown in FIG. The shape of the opening 104 in the c) is smoothly circular or roughly diamond shaped.

By the way, in the MIG head, when the head chips having the required chip widths are cut out from the magnetic head block 106, cracks or the like may occur in the head chips, or the metal magnetic film 102 may be peeled off. In many cases, it is a big problem in yield.

It is considered that the main cause of the problem is that the track width restricting grooves 101 or the openings 104 of the magnetic core half block 103 or the magnetic head block 106 have such a shape. This is considered to be due to the strong stress applied to the magnetic metal film 102 and the glass material 105 due to the shape of the track width restricting groove 101 or the opening 104 when cutting with each head chip.

This invention is made | formed in view of the above-mentioned subject, The objective of this invention can suppress cracking, peeling of a magnetic metal film, etc. which are easy to generate | occur | produce in a magnetic core at the time of manufacture, and the yield of a product and reliability of a product are large An object of the present invention is to provide a manufacturing method of a magnetic head that can be improved.

According to the present invention, a magnetic metal film made of a soft magnetic metal material is formed on at least one side of a gap surface of a pair of magnetic core halves, and the pair of magnetic cores face each other so that the gap faces each other. In the manufacturing method of the metal-in-gap type magnetic head which consists of a process of forming a magnetic head block in the state which joined the half body, before each process of forming a magnetic head block, a cross section is polygonal in each of the said pair of magnetic core half bodies. Forming a plurality of track width restricting grooves having at least two bends, and forming the magnetic head block includes introducing a glass material for fusion into the plurality of polygonal track width restricting grooves; When the magnetic head block is cut to the required width including a gap within the width of each head chip, and the polygonal track width restricting groove is equally divided by the number of bends, The bent portion of the width regulating groove to one exists, there is provided a manufacturing method of the magnetic head characterized in that the partition in each head chip.

In the MIG head according to the present invention, each track width restricting groove of the magnetic core half block, which is the base of the magnetic head at the time of manufacture, is formed in a polygonal cross section perpendicular to the longitudinal direction and has a plurality of bent portions. .

The MIG head has a metal magnetic film at the position of the magnetic gap in parallel with the magnetic gap, and at the time of manufacture, the MIG head is cut out from the magnetic head block composed of a pair of magnetic core half blocks. Due to the difference in the coefficient of thermal expansion of the magnetic core, the glass material, and the metal magnetic film, which are the components of the head, the stress generated in the glass material is alleviated in the bent portion, and the durability to the work stress is greatly improved. Further, the effective total stress acting on the metal magnetic film formed in each of the track width restricting grooves is also alleviated, so that peeling of the metal magnetic film is suppressed.

Here, it is necessary that two or more bends are formed for practical use. In this example, three bends are formed in the track width restricting groove. This is because the effective total stress applied to the magnetic metal film is considered to decrease exponentially as the number of the bent portions increases. By approximating, the total stress F is assumed to be the number of bends in N, so that F = k 2 ^-N (k is a proportional constant).

In the present invention, the bending angle, which is a value indicating the degree of bending in the respective bending portions, is 8 ° or more, and the track width restricting grooves are curved in the direction orthogonal to the magnetic gap in the cross section perpendicular to the track direction. By dividing the MIG head so that one bent portion exists in each divided area at the time of equal division, the deviation of the position of the bent portion in the cross-sectional shape of the track width restricting groove is reduced, and the stress applied to each bent portion is made uniform. Therefore, the effective total stress applied to the magnetic metal film is further alleviated.

According to the present invention, a plurality of track width restricting grooves are formed on one main surface, and magnetic core blocks formed by forming a magnetic metal film made of a soft magnetic metal material on one main surface of the main surface are bonded to each other via a gap material to form a magnetic head block. By cutting the magnetic head block, when the head chip of the magnetic head is manufactured, the track width restricting groove is formed in a polygonal cross section and at least two bends are formed so as to be generated in the magnetic core at the time of manufacture. It is possible to suppress easy cracking, peeling of the magnetic metal film, and the like, and to significantly improve the yield and reliability of the product.

Next, specific examples of the magnetic head according to the present invention will be described in detail with reference to the drawings.

In the manufacturing method of the magnetic head of the present invention, a plurality of band-shaped track width restricting grooves are formed on one main surface with a gap width, and a metal magnetic film made of a soft magnetic metal material is formed on one main surface. By forming a film to form a gap surface, a magnetic core half block is formed. Next, a pair of the magnetic core half blocks are bonded to each other via a gap material to form a magnetic head block having a plurality of magnetic gaps. Then, the head chip having the required chip width is cut out from the magnetic head block. Thus, a so-called metal-in-gap type magnetic head (hereinafter, simply referred to as MIG head) is produced.

As shown in Fig. 5, the magnetic core of the MIG head is made of a soft magnetic metal material around each of the track width restricting grooves 3 of the pair of magnetic core bodies 1 and 2. A metal magnetic film 4 is formed, and each of these magnetic core halves 1 and 2 is bonded to each other via a gap material on the main surface thereof to form a magnetic gap. When these magnetic core bodies 1 and 2 are bonded together, the glass material 5 for fusion flows into each track width restricting groove 3, and the magnetic core bodies 1 and 2 are joined. have.

Here, the magnetic core halves (1) and (2) are formed with guide grooves (not shown) for winding coils for flowing a recording current, and the magnetic core halves (1) have winding grooves (6). Is formed. The winding not shown in these guide grooves and winding grooves 6 is performed to constitute the MIG head.

Here, the track width restricting grooves 3 formed in the magnetic core halves 1 and 2 of the MIC head have a bent portion 10 one by one symmetrically about the magnetic gap g as shown in the figure. Formed.

In forming the track width limiting grooves 3 in such a shape, when the MIG head is manufactured, the track width limiting grooves 3 have a shape shown in FIG. A plurality of the track width restricting grooves 3 are formed in one main surface of the magnetic core half block, which is the base of the core half bodies 1 and 2.

That is, in manufacturing the MIG head, first, as shown in FIG. 6, a plurality of band-shaped track width regulating grooves 3 are formed on one main surface of each of the pair of magnetic core half blocks 12 and 13. ) Is formed into a predetermined shape described later with a gap width interval W by cutting or grinding. Further, the winding groove 14 (later referred to as the winding groove 6) is formed in the magnetic core half block 12 only.

Subsequently, on one main surface on which the track width restricting grooves 3 of the magnetic core half blocks 12 and 13 are formed, the metal magnetic film 4 made of a soft magnetic metal material has a thickness of several micrometers. Sputter film-forming is formed uniformly over the whole. Thereafter, the magnetic core half blocks 12 and 13 are joined together so that the surfaces to form the magnetic gap g coincide with each other. Here, as shown in FIG. 7, the glass material 5 for fusion welding to each of the openings 15 formed by joining the track width regulating grooves 3 of the magnetic core half blocks 12 and 13 together. The magnetic head block 16 is manufactured by joining a pair of magnetic core half blocks 12 and 13 by introducing?

At this time, each of the openings 15 of the magnetic head block 16 has a shape as shown in FIG. In other words, the track width restricting grooves 3 of the magnetic core half blocks 12 and 13 forming the openings 15 by joining are polygonal in cross section orthogonal to the longitudinal direction, and here three It is formed in the shape which has the bending part 21, 22, and 23. As shown in FIG. Thus, in the said MIG head, it is necessary to form two or more said bending parts.

Here, it is preferable to make the bending angle which is a value which shows the degree of the bending in each bending part 21, 22, and 23 to be 8 degrees or more. Here, the bend angle is formed between a line extending from one side of the bend and two sides of each side forming the track width restricting grooves 3, centered on a bend, and the other side. It is defined as the angle which becomes. That is, in the present embodiment, as shown in FIG. 8, the angles formed by the sides and the broken lines in the bends 21, 22, and 23 are the bend angles A, B, and C, respectively. .

Further, when the track width restricting grooves 3 are equally divided by the number of bends in the direction orthogonal to the magnetic gap g in the cross section orthogonal to the longitudinal direction, each track width so that one bend is present in each divided area. It is preferable to form the regulating groove 3. In this embodiment, as shown by the broken line in FIG. 8, the bent portions 21, 22, and 23 are present in the respective regions divided into three in the direction orthogonal to the magnetic gap g.

Then, the magnetic head block 16 manufactured as described above is cut at a position including the two openings 15 as shown by two broken lines in FIG. 7, and each head as shown in FIG. The chip 24 is produced. Subsequently, the joint width processing as shown by the broken line is performed on the surface M to be the medium slide contact surface of each head chip 24, and the magnetic core shown in FIG. The MIG head is completed by performing post processing.

As described above, in the MIG head, the track width restricting grooves 3 of the magnetic core half blocks 12 and 13, which are the bases of the MIG head at the time of manufacture, are perpendicular to the longitudinal direction thereof. It is formed in polygonal shape in cross section, and has the curved parts 21, 22, and 23. As shown in FIG.

The MIG head has a metal magnetic film 4 at the position of the magnetic gap g in parallel with the magnetic gap g. At the time of manufacture, the MIG head has a magnetic head composed of a pair of magnetic core half blocks 12 and 13. When the head chips 24 are cut out from the lock 16, the glass is caused due to the difference in thermal expansion coefficients of the materials of the magnetic core, the glass material 5, and the metal magnetic film 4, which are the components of the MIG head. The stress generated in the material 5 is relaxed in the bent portions 21, 22, and 23, and the durability against work stress is greatly improved. Further, the effective total stress acting on the metal magnetic film 4 formed in each of the track width restricting grooves 3 is also alleviated, so that peeling of the metal magnetic film 4 is suppressed.

Here, it is necessary that at least two bent portions (three in this example) are formed in the track width restricting groove 3 for practical use. This is because the effective total stress applied to the magnetic metal film 4 is considered to decrease exponentially as the number of the bent portions increases. Specifically, the stress applied to the magnetic metal film 4 at each bent portion When approximated to be decomposed in two directions, the total stress F becomes F = k 2 ^-N (k is a proportionality constant) with the number of bends as N.

Moreover, in this invention, the bending angle which is the value which shows the degree of curvature in each said bending part is 8 degree or more, and each track width regulation groove 3 is orthogonal to the magnetic gap g in the cross section orthogonal to the longitudinal direction. By dividing the number of bends into three equal parts (in this example, three equal parts), the MIG heads are formed so that one bend is present in each divided area, whereby the position of the bends in the cross-sectional shape of the track width restricting groove is determined. Deviation is reduced, and the stress applied to each bent portion becomes uniform, so that the effective total stress applied to the magnetic metal film 4 is further alleviated.

Here, the conventional MIG head (head B) made of the magnetic core half block 103 having the MIG head (head A) of the above embodiment and each track width restricting groove 101 of substantially semicircular shape as shown in FIG. The experimental example which investigated about the processing state at the time of making into the magnetic head block 16 and 106, respectively, is demonstrated.

This experiment was carried out to investigate the degree of defective processing when the head chips of the respective MIG heads were cut out from the magnetic head blocks 16 and 106. Specifically, the head chips of the predetermined number of MIG heads produced were applied to the head chips. It is an experiment which investigated the ratio A which is the ratio of which the damage, such as a crack, generate | occur | produced, and the ratio B which is the ratio of the peeling of the magnetic metal films 4 and 102 which occurred.

Here, with respect to the head A, the bending angles A, B, and C in the bending portions 21, 22, and 23 shown in FIG. 8 are assumed to be the bending angle A = the bending angle C. The angle D between the normal to the gap g and the line segment k was defined as the angle D = 8 °. Then, sample 1 having a bend angle A = 32 ° and bend angle B = 100 ° as shown in FIG. 10, and sample 2 having a bend angle A = 15 ° and bend angle B = 90 ° as shown in FIG. The three samples of the sample 3 of the bending angle A = 30 degrees and the bending angle B = 150 degrees as shown to FIG. 12 and FIG. 12 were investigated.

The results of the above experiments are as follows. For the head B of the related art, the ratio A is 7.2% and the ratio B is 4.1%. The sample A of the head A has a ratio A of 0.5% and the ratio B of 4.1%. 0.1%, for sample 2, the ratio A was 1.2%, the ratio B was 0.1%, and for sample 3, the ratio A was 1.0% and the ratio B was 0.8%, showing very good values for all samples.

As such, the magnetic head of the above embodiment showed a clear advantage over the conventional magnetic head.

1 is a perspective view schematically showing an aspect in which track width restricting grooves and the like of a plurality of bands are formed in each magnetic core half block of a conventional magnetic head.

FIG. 2 is a perspective view schematically showing an embodiment in which a pair of magnetic core half blocks of a conventional magnetic head are bonded together and bonded with a glass material for fusion welding; FIG.

3 is a schematic diagram showing an example of the shape of each opening of the conventional magnetic head.

4 is a schematic diagram showing another example of the shape of each opening of the conventional magnetic head.

5 is a perspective view schematically showing a magnetic head of an embodiment of the present invention.

6 is a perspective view schematically showing an embodiment in which a plurality of band-shaped track width restricting grooves are formed in each magnetic core half block.

FIG. 7 is a perspective view schematically showing an embodiment in which a pair of magnetic core half blocks are bonded together and joined together with a glass material for welding.

8 is a schematic diagram showing the shape of each opening formed in the magnetic head block.

9 is a perspective view schematically showing each head chip manufactured.

10 is a schematic diagram showing the shape of each opening of a sample of a magnetic head in an experimental example.

FIG. 11 is a schematic diagram showing the shape of each opening of another sample of the magnetic head in the experimental example. FIG.

12 is a schematic diagram showing the shape of each opening of another sample of the magnetic head in the experimental example.

* Explanation of symbols for the main parts of the drawings

(1), (2): Magnetic core body, (3): Track width regulation groove, (4): Magnetic metal film, (5): Glass material, (6): Winding groove, (12), (13) : Magnetic core half block, (15): Opening, (16): Magnetic head block, (21), (22), (23): Bends, (24): Head chip, A, B, C: Bend angle

Claims (2)

A metal magnetic film made of a soft magnetic metal material is formed on at least one of the gap faces of the pair of magnetic core halves, and the pair of magnetic core halves are bonded together so that the gap faces each other. As a manufacturing method of manufacturing a metal-in-gap type magnetic head consisting of forming a magnetic head block in Before forming the magnetic head block, a plurality of track width restricting grooves are formed in each of the pair of magnetic core halves, each having a polygonal cross section and having at least two bends. Forming the magnetic head block includes the step of introducing a glass material for fusion into the plurality of polygonal track width regulation groove, The magnetic head block is cut into required widths including gaps within the width of each head chip, When the polygonal track width regulating groove is equally divided by the number of the bent portions, one curved portion of the track width regulating groove is present in each divided area. When the track width regulation groove is formed in the magnetic head block serving as the magnetic core half, one track width regulation groove formed in the magnetic head block has a bent portion having two or more kinds of angles. The method of manufacturing a magnetic head according to claim 1, wherein a bending angle at each bent portion is 8 ° or more.